Hi, guys
In the Shadow map sample in ShaderX2, The author draw the shadow like that:
1: Disable the color writing, and render all the scene to generate the depth.
2: use ZFUNC_EQUAL to render the scene with each light

Here is the confusion: If i use the ZFUNC_EQUAL and render something with the same method above, i will encounter the depth competition, but the sample not. Further more, i check the bias state in pix, the depth bias is 0.

so how can i avoid the depth competition problem with ZFUNC_EQUAL ?
Appreciate for any clues about it.